Burning the bootloader via ISP (advanced)

This is for advanced users who want to burn the bootloader with an external ISP directly. You can do this with your program if choice (e.g. avr-dude) or use the Arduino IDE and select the correct MCU, board, bootloader, programmer and hit "burn bootloader".

You can either use any official ISP or let your Arduino Uno/Mega/Leonardo/Micro/16u2 act as ISP.

HoodLoader2 Fuses:
low_fuses=0xEF
high_fuses=0xD8 (boot to Bootloader)
extended_fuses=0xFC (no HWBE)
unlock_bits=0x3F
lock_bits=0x0F

Official DFU + USB-Serial Fuses:
low_fuses=0xEF
high_fuses=0xD9 (boot to program)
extended_fuses=0xF4 (with HWBE)
unlock_bits=0x3F
lock_bits=0x0F